/**
  ******************************************************************************
    @file    stm32f4xx_exti.c
    @author  MCD Application Team
    @version V1.4.0
    @date    04-August-2014
    @brief   This file provides firmware functions to manage the following
             functionalities of the EXTI peripheral:
              + Initialization and Configuration
              + Interrupts and flags management

    @verbatim

    ===============================================================================
                              ##### EXTI features #####
    ===============================================================================

    [..] External interrupt/event lines are mapped as following:
    (#) All available GPIO pins are connected to the 16 external
       interrupt/event lines from EXTI0 to EXTI15.
    (#) EXTI line 16 is connected to the PVD Output
    (#) EXTI line 17 is connected to the RTC Alarm event
    (#) EXTI line 18 is connected to the USB OTG FS Wakeup from suspend event
    (#) EXTI line 19 is connected to the Ethernet Wakeup event
    (#) EXTI line 20 is connected to the USB OTG HS (configured in FS) Wakeup event
    (#) EXTI line 21 is connected to the RTC Tamper and Time Stamp events
    (#) EXTI line 22 is connected to the RTC Wakeup event

                       ##### How to use this driver #####
    ===============================================================================

    [..] In order to use an I/O pin as an external interrupt source, follow steps
      below:
    (#) Configure the I/O in input mode using GPIO_Init()
    (#) Select the input source pin for the EXTI line using SYSCFG_EXTILineConfig()
    (#) Select the mode(interrupt, event) and configure the trigger
       selection (Rising, falling or both) using EXTI_Init()
    (#) Configure NVIC IRQ channel mapped to the EXTI line using NVIC_Init()

    [..]
    (@) SYSCFG APB clock must be enabled to get write access to SYSCFG_EXTICRx
       registers using RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);

    @endverbatim

  ******************************************************************************
    @attention

    <h2><center>&copy; COPYRIGHT 2014 STMicroelectronics</center></h2>

    Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
    You may not use this file except in compliance with the License.
    You may obtain a copy of the License at:

           http://www.st.com/software_license_agreement_liberty_v2

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.

  ******************************************************************************
*/

/* Includes ------------------------------------------------------------------*/
#include "stm32f4xx_exti.h"

/** @addtogroup STM32F4xx_StdPeriph_Driver
    @{
*/

/** @defgroup EXTI
    @brief EXTI driver modules
    @{
*/

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/

#define EXTI_LINENONE    ((uint32_t)0x00000)  /* No interrupt selected */

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/* Private functions ---------------------------------------------------------*/

/** @defgroup EXTI_Private_Functions
    @{
*/

/** @defgroup EXTI_Group1 Initialization and Configuration functions
    @brief   Initialization and Configuration functions

    @verbatim
    ===============================================================================
             ##### Initialization and Configuration functions #####
    ===============================================================================

    @endverbatim
    @{
*/

/**
    @brief  Deinitializes the EXTI peripheral registers to their default reset values.
    @param  None
    @retval None
*/
void EXTI_DeInit(void)
{
	EXTI->IMR = 0x00000000;
	EXTI->EMR = 0x00000000;
	EXTI->RTSR = 0x00000000;
	EXTI->FTSR = 0x00000000;
	EXTI->PR = 0x007FFFFF;
}

/**
    @brief  Initializes the EXTI peripheral according to the specified
            parameters in the EXTI_InitStruct.
    @param  EXTI_InitStruct: pointer to a EXTI_InitTypeDef structure
            that contains the configuration information for the EXTI peripheral.
    @retval None
*/
void EXTI_Init(EXTI_InitTypeDef* EXTI_InitStruct)
{
	uint32_t tmp = 0;
	/* Check the parameters */
	assert_param(IS_EXTI_MODE(EXTI_InitStruct->EXTI_Mode));
	assert_param(IS_EXTI_TRIGGER(EXTI_InitStruct->EXTI_Trigger));
	assert_param(IS_EXTI_LINE(EXTI_InitStruct->EXTI_Line));
	assert_param(IS_FUNCTIONAL_STATE(EXTI_InitStruct->EXTI_LineCmd));
	tmp = (uint32_t)EXTI_BASE;
	if (EXTI_InitStruct->EXTI_LineCmd != DISABLE)
	{
		/* Clear EXTI line configuration */
		EXTI->IMR &= ~EXTI_InitStruct->EXTI_Line;
		EXTI->EMR &= ~EXTI_InitStruct->EXTI_Line;
		tmp += EXTI_InitStruct->EXTI_Mode;
		*(__IO uint32_t *) tmp |= EXTI_InitStruct->EXTI_Line;
		/* Clear Rising Falling edge configuration */
		EXTI->RTSR &= ~EXTI_InitStruct->EXTI_Line;
		EXTI->FTSR &= ~EXTI_InitStruct->EXTI_Line;
		/* Select the trigger for the selected external interrupts */
		if (EXTI_InitStruct->EXTI_Trigger == EXTI_Trigger_Rising_Falling)
		{
			/* Rising Falling edge */
			EXTI->RTSR |= EXTI_InitStruct->EXTI_Line;
			EXTI->FTSR |= EXTI_InitStruct->EXTI_Line;
		}
		else
		{
			tmp = (uint32_t)EXTI_BASE;
			tmp += EXTI_InitStruct->EXTI_Trigger;
			*(__IO uint32_t *) tmp |= EXTI_InitStruct->EXTI_Line;
		}
	}
	else
	{
		tmp += EXTI_InitStruct->EXTI_Mode;
		/* Disable the selected external lines */
		*(__IO uint32_t *) tmp &= ~EXTI_InitStruct->EXTI_Line;
	}
}

/**
    @brief  Fills each EXTI_InitStruct member with its reset value.
    @param  EXTI_InitStruct: pointer to a EXTI_InitTypeDef structure which will
            be initialized.
    @retval None
*/
void EXTI_StructInit(EXTI_InitTypeDef* EXTI_InitStruct)
{
	EXTI_InitStruct->EXTI_Line = EXTI_LINENONE;
	EXTI_InitStruct->EXTI_Mode = EXTI_Mode_Interrupt;
	EXTI_InitStruct->EXTI_Trigger = EXTI_Trigger_Falling;
	EXTI_InitStruct->EXTI_LineCmd = DISABLE;
}

/**
    @brief  Generates a Software interrupt on selected EXTI line.
    @param  EXTI_Line: specifies the EXTI line on which the software interrupt
            will be generated.
            This parameter can be any combination of EXTI_Linex where x can be (0..22)
    @retval None
*/
void EXTI_GenerateSWInterrupt(uint32_t EXTI_Line)
{
	/* Check the parameters */
	assert_param(IS_EXTI_LINE(EXTI_Line));
	EXTI->SWIER |= EXTI_Line;
}

/**
    @}
*/

/** @defgroup EXTI_Group2 Interrupts and flags management functions
    @brief   Interrupts and flags management functions

    @verbatim
    ===============================================================================
             ##### Interrupts and flags management functions #####
    ===============================================================================

    @endverbatim
    @{
*/

/**
    @brief  Checks whether the specified EXTI line flag is set or not.
    @param  EXTI_Line: specifies the EXTI line flag to check.
             This parameter can be EXTI_Linex where x can be(0..22)
    @retval The new state of EXTI_Line (SET or RESET).
*/
FlagStatus EXTI_GetFlagStatus(uint32_t EXTI_Line)
{
	FlagStatus bitstatus = RESET;
	/* Check the parameters */
	assert_param(IS_GET_EXTI_LINE(EXTI_Line));
	if ((EXTI->PR & EXTI_Line) != (uint32_t)RESET)
		bitstatus = SET;
	else
		bitstatus = RESET;
	return bitstatus;
}

/**
    @brief  Clears the EXTI's line pending flags.
    @param  EXTI_Line: specifies the EXTI lines flags to clear.
             This parameter can be any combination of EXTI_Linex where x can be (0..22)
    @retval None
*/
void EXTI_ClearFlag(uint32_t EXTI_Line)
{
	/* Check the parameters */
	assert_param(IS_EXTI_LINE(EXTI_Line));
	EXTI->PR = EXTI_Line;
}

/**
    @brief  Checks whether the specified EXTI line is asserted or not.
    @param  EXTI_Line: specifies the EXTI line to check.
             This parameter can be EXTI_Linex where x can be(0..22)
    @retval The new state of EXTI_Line (SET or RESET).
*/
ITStatus EXTI_GetITStatus(uint32_t EXTI_Line)
{
	FlagStatus bitstatus = RESET;
	/* Check the parameters */
	assert_param(IS_GET_EXTI_LINE(EXTI_Line));
	if ((EXTI->PR & EXTI_Line) != (uint32_t)RESET)
		bitstatus = SET;
	else
		bitstatus = RESET;
	return bitstatus;
}

/**
    @brief  Clears the EXTI's line pending bits.
    @param  EXTI_Line: specifies the EXTI lines to clear.
             This parameter can be any combination of EXTI_Linex where x can be (0..22)
    @retval None
*/
void EXTI_ClearITPendingBit(uint32_t EXTI_Line)
{
	/* Check the parameters */
	assert_param(IS_EXTI_LINE(EXTI_Line));
	EXTI->PR = EXTI_Line;
}

/**
    @}
*/

/**
    @}
*/

/**
    @}
*/

/**
    @}
*/

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
